[v4] scsi: ufs: ufs-sysfs: Expose UFS power info

Having UFS power info available in sysfs makes it easier to tell the state
of the link during runtime considering we have a bunch of power saving
features and various combinations for backward compatibility.

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Can Guo <quic_cang@quicinc.com>
---

v3 -> v4:
Incorporated comments from Bart and Mani

v2 -> v3:
1. For mode/gear/rate/dev_pm/link_status, print texts instead of numbers
2. Removed number<->text explanations for mode/rate/gear/dev_pm/link_status in Documentation/ABI/testing/sysfs-driver-ufs

v1 -> v2:
1. Incorporated comments from Bart, Nitin and Mani.
2. Added explanations for lane/mode/rate/gear/dev_pm/link_status in Documentation/ABI/testing/sysfs-driver-ufs

---

 Documentation/ABI/testing/sysfs-driver-ufs |  49 ++++++++++++
 drivers/ufs/core/ufs-sysfs.c               | 120 +++++++++++++++++++++++++++++
 include/ufs/unipro.h                       |   4 +-
 3 files changed, 171 insertions(+), 2 deletions(-)

> 
> Having UFS power info available in sysfs makes it easier to tell the state of
> the link during runtime considering we have a bunch of power saving
> features and various combinations for backward compatibility.
> 
> Reviewed-by: Manivannan Sadhasivam
> <manivannan.sadhasivam@linaro.org>
> Reviewed-by: Bean Huo <beanhuo@micron.com>
> Reviewed-by: Bart Van Assche <bvanassche@acm.org>
> Signed-off-by: Can Guo <quic_cang@quicinc.com>
Reviewed-by: Avri Altman <avri.altman@wdc.com>

> ---
> 
> v3 -> v4:
> Incorporated comments from Bart and Mani
> 
> v2 -> v3:
> 1. For mode/gear/rate/dev_pm/link_status, print texts instead of numbers 2.
> Removed number<->text explanations for
> mode/rate/gear/dev_pm/link_status in Documentation/ABI/testing/sysfs-
> driver-ufs
> 
> v1 -> v2:
> 1. Incorporated comments from Bart, Nitin and Mani.
> 2. Added explanations for lane/mode/rate/gear/dev_pm/link_status in
> Documentation/ABI/testing/sysfs-driver-ufs
> 
> ---
> 
>  Documentation/ABI/testing/sysfs-driver-ufs |  49 ++++++++++++
>  drivers/ufs/core/ufs-sysfs.c               | 120
> +++++++++++++++++++++++++++++
>  include/ufs/unipro.h                       |   4 +-
>  3 files changed, 171 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/ABI/testing/sysfs-driver-ufs
> b/Documentation/ABI/testing/sysfs-driver-ufs
> index 0c7efaf..b73067b 100644
> --- a/Documentation/ABI/testing/sysfs-driver-ufs
> +++ b/Documentation/ABI/testing/sysfs-driver-ufs
> @@ -1223,6 +1223,55 @@ Description:     This file shows the total latency
> (in micro seconds) of write
> 
>                 The file is read only.
> 
> +What:          /sys/bus/platform/drivers/ufshcd/*/power_info/lane
> +What:          /sys/bus/platform/devices/*.ufs/power_info/lane
> +Date:          September 2023
> +Contact:       Can Guo <quic_cang@quicinc.com>
> +Description:   This file shows how many lanes are enabled on the UFS link,
> +               i.e., an output 2 means UFS link is operating with 2 lanes.
> +
> +               The file is read only.
> +
> +What:          /sys/bus/platform/drivers/ufshcd/*/power_info/mode
> +What:          /sys/bus/platform/devices/*.ufs/power_info/mode
> +Date:          September 2023
> +Contact:       Can Guo <quic_cang@quicinc.com>
> +Description:   This file shows the PA power mode of UFS.
> +
> +               The file is read only.
> +
> +What:          /sys/bus/platform/drivers/ufshcd/*/power_info/rate
> +What:          /sys/bus/platform/devices/*.ufs/power_info/rate
> +Date:          September 2023
> +Contact:       Can Guo <quic_cang@quicinc.com>
> +Description:   This file shows the speed rate of UFS link.
> +
> +               The file is read only.
> +
> +What:          /sys/bus/platform/drivers/ufshcd/*/power_info/gear
> +What:          /sys/bus/platform/devices/*.ufs/power_info/gear
> +Date:          September 2023
> +Contact:       Can Guo <quic_cang@quicinc.com>
> +Description:   This file shows the gear of UFS link.
> +
> +               The file is read only.
> +
> +What:          /sys/bus/platform/drivers/ufshcd/*/power_info/dev_pm
> +What:          /sys/bus/platform/devices/*.ufs/power_info/dev_pm
> +Date:          September 2023
> +Contact:       Can Guo <quic_cang@quicinc.com>
> +Description:   This file shows the UFS device power mode.
> +
> +               The file is read only.
> +
> +What:          /sys/bus/platform/drivers/ufshcd/*/power_info/link_state
> +What:          /sys/bus/platform/devices/*.ufs/power_info/link_state
> +Date:          September 2023
> +Contact:       Can Guo <quic_cang@quicinc.com>
> +Description:   This file shows the state of UFS link.
> +
> +               The file is read only.
> +
>  What:
> /sys/bus/platform/drivers/ufshcd/*/device_descriptor/wb_presv_us_en
>  What:
> /sys/bus/platform/devices/*.ufs/device_descriptor/wb_presv_us_en
>  Date:          June 2020
> diff --git a/drivers/ufs/core/ufs-sysfs.c b/drivers/ufs/core/ufs-sysfs.c index
> c959064..05b10ca 100644
> --- a/drivers/ufs/core/ufs-sysfs.c
> +++ b/drivers/ufs/core/ufs-sysfs.c
> @@ -7,9 +7,56 @@
>  #include <asm/unaligned.h>
> 
>  #include <ufs/ufs.h>
> +#include <ufs/unipro.h>
>  #include "ufs-sysfs.h"
>  #include "ufshcd-priv.h"
> 
> +static const char *ufs_pa_pwr_mode_to_string(enum ufs_pa_pwr_mode
> mode)
> +{
> +       switch (mode) {
> +       case FAST_MODE:         return "FAST_MODE";
> +       case SLOW_MODE:         return "SLOW_MODE";
> +       case FASTAUTO_MODE:     return "FASTAUTO_MODE";
> +       case SLOWAUTO_MODE:     return "SLOWAUTO_MODE";
> +       default:                return "UNKNOWN";
> +       }
> +}
> +
> +static const char *ufs_hs_gear_rate_to_string(enum ufs_hs_gear_rate
> +rate) {
> +       switch (rate) {
> +       case PA_HS_MODE_A:      return "HS_RATE_A";
> +       case PA_HS_MODE_B:      return "HS_RATE_B";
> +       default:                return "UNKNOWN";
> +       }
> +}
> +
> +static const char *ufs_pwm_gear_to_string(enum ufs_pwm_gear_tag gear)
> {
> +       switch (gear) {
> +       case UFS_PWM_G1:        return "PWM_GEAR1";
> +       case UFS_PWM_G2:        return "PWM_GEAR2";
> +       case UFS_PWM_G3:        return "PWM_GEAR3";
> +       case UFS_PWM_G4:        return "PWM_GEAR4";
> +       case UFS_PWM_G5:        return "PWM_GEAR5";
> +       case UFS_PWM_G6:        return "PWM_GEAR6";
> +       case UFS_PWM_G7:        return "PWM_GEAR7";
> +       default:                return "UNKNOWN";
> +       }
> +}
> +
> +static const char *ufs_hs_gear_to_string(enum ufs_hs_gear_tag gear) {
> +       switch (gear) {
> +       case UFS_HS_G1: return "HS_GEAR1";
> +       case UFS_HS_G2: return "HS_GEAR2";
> +       case UFS_HS_G3: return "HS_GEAR3";
> +       case UFS_HS_G4: return "HS_GEAR4";
> +       case UFS_HS_G5: return "HS_GEAR5";
> +       default:        return "UNKNOWN";
> +       }
> +}
> +
>  static const char *ufshcd_uic_link_state_to_string(
>                         enum uic_link_state state)  { @@ -628,6 +675,78 @@ static
> const struct attribute_group ufs_sysfs_monitor_group = {
>         .attrs = ufs_sysfs_monitor_attrs,  };
> 
> +static ssize_t lane_show(struct device *dev, struct device_attribute *attr,
> +                        char *buf)
> +{
> +       struct ufs_hba *hba = dev_get_drvdata(dev);
> +
> +       return sysfs_emit(buf, "%u\n", hba->pwr_info.lane_rx); }
> +
> +static ssize_t mode_show(struct device *dev, struct device_attribute *attr,
> +                        char *buf)
> +{
> +       struct ufs_hba *hba = dev_get_drvdata(dev);
> +
> +       return sysfs_emit(buf, "%s\n",
> +ufs_pa_pwr_mode_to_string(hba->pwr_info.pwr_rx));
> +}
> +
> +static ssize_t rate_show(struct device *dev, struct device_attribute *attr,
> +                        char *buf)
> +{
> +       struct ufs_hba *hba = dev_get_drvdata(dev);
> +
> +       return sysfs_emit(buf, "%s\n",
> +ufs_hs_gear_rate_to_string(hba->pwr_info.hs_rate));
> +}
> +
> +static ssize_t gear_show(struct device *dev, struct device_attribute *attr,
> +                        char *buf)
> +{
> +       struct ufs_hba *hba = dev_get_drvdata(dev);
> +
> +       return sysfs_emit(buf, "%s\n", hba->pwr_info.hs_rate ?
> +                         ufs_hs_gear_to_string(hba->pwr_info.gear_rx) :
> +
> +ufs_pwm_gear_to_string(hba->pwr_info.gear_rx));
> +}
> +
> +static ssize_t dev_pm_show(struct device *dev, struct device_attribute
> *attr,
> +                          char *buf)
> +{
> +       struct ufs_hba *hba = dev_get_drvdata(dev);
> +
> +       return sysfs_emit(buf, "%s\n",
> +ufshcd_ufs_dev_pwr_mode_to_string(hba->curr_dev_pwr_mode));
> +}
> +
> +static ssize_t link_state_show(struct device *dev,
> +                              struct device_attribute *attr, char *buf)
> +{
> +       struct ufs_hba *hba = dev_get_drvdata(dev);
> +
> +       return sysfs_emit(buf, "%s\n",
> +ufshcd_uic_link_state_to_string(hba->uic_link_state));
> +}
> +
> +static DEVICE_ATTR_RO(lane);
> +static DEVICE_ATTR_RO(mode);
> +static DEVICE_ATTR_RO(rate);
> +static DEVICE_ATTR_RO(gear);
> +static DEVICE_ATTR_RO(dev_pm);
> +static DEVICE_ATTR_RO(link_state);
> +
> +static struct attribute *ufs_power_info_attrs[] = {
> +       &dev_attr_lane.attr,
> +       &dev_attr_mode.attr,
> +       &dev_attr_rate.attr,
> +       &dev_attr_gear.attr,
> +       &dev_attr_dev_pm.attr,
> +       &dev_attr_link_state.attr,
> +       NULL
> +};
> +
> +static const struct attribute_group ufs_sysfs_power_info_group = {
> +       .name = "power_info",
> +       .attrs = ufs_power_info_attrs,
> +};
> +
>  static ssize_t ufs_sysfs_read_desc_param(struct ufs_hba *hba,
>                                   enum desc_idn desc_id,
>                                   u8 desc_index, @@ -1233,6 +1352,7 @@ static const
> struct attribute_group *ufs_sysfs_groups[] = {
>         &ufs_sysfs_default_group,
>         &ufs_sysfs_capabilities_group,
>         &ufs_sysfs_monitor_group,
> +       &ufs_sysfs_power_info_group,
>         &ufs_sysfs_device_descriptor_group,
>         &ufs_sysfs_interconnect_descriptor_group,
>         &ufs_sysfs_geometry_descriptor_group,
> diff --git a/include/ufs/unipro.h b/include/ufs/unipro.h index
> 256eb3a..360e124 100644
> --- a/include/ufs/unipro.h
> +++ b/include/ufs/unipro.h
> @@ -193,7 +193,7 @@
>  #define DME_LocalAFC0ReqTimeOutVal             0xD043
> 
>  /* PA power modes */
> -enum {
> +enum ufs_pa_pwr_mode {
>         FAST_MODE       = 1,
>         SLOW_MODE       = 2,
>         FASTAUTO_MODE   = 4,
> @@ -205,7 +205,7 @@ enum {
>  #define PWRMODE_RX_OFFSET      4
> 
>  /* PA TX/RX Frequency Series */
> -enum {
> +enum ufs_hs_gear_rate {
>         PA_HS_MODE_A    = 1,
>         PA_HS_MODE_B    = 2,
>  };
> --
> 2.7.4

Can,

> Having UFS power info available in sysfs makes it easier to tell the
> state of the link during runtime considering we have a bunch of power
> saving features and various combinations for backward compatibility.

Applied to 6.8/scsi-staging, thanks!